Harmonic ringer.



J. ERIGKSON. HABMONIG RINGER. APPLICATION FILED nov. so, 1908.

I'HE NORRIS PETER: um. PHOTO-LITHQ. WASHINGTON. D C.

' UNITED STATES PATENT OFFICE. J

I JOHN RIOKSON, OF CHICAGO, ILLINOIS, AssIGNOn T0 AUTOMATIC ELECTRIC lCOMPANY, oFcHIcAGo; ILLIN0IS,IA CORPORATION or ILLINOIS.

' IIAnMoNIc RINGER.

To all whom it may concern I Be it known that IQJOHN Erickson, a

citizen of the United States of America, and resident'of Chicago, (lookcounty, Ill1 bratory armature and striker the provision I of improvedmeans for holding the said strikerunder spring tension; .the provisionof improved means for adjusting the vibratory periodof'saidstrikerthat"is' to say, for tuning the same to respondto a certan frequency of current; the provision of an' improved arrangementwhereby fiat spr ngs and certain other 'featuresfheretoforeemployedare'not necessary, the provision of improved means for ad ust1ng thepolepieces of the ringer; and the provision of certain details andfeatures ofimprovement and combinations tending to increase theefliciencv, of a ringer of this particular char acter." f

To the foregoing and other useful 'en'ds, my invention consists inmatters hereinafter set forth and claimed.

In the accompanying drawings Figure 1 is a front elevation of anelectric ringer embodying the principles of my Invention.

Fig. 2- is a detail View illustrating the I method of mounting thearmature of the ringer. Fig. 3 is a, horizontal section on line 3-3 inFig. 1. Fig. 'Ais' a detail sectional view illustrating the method ofadjustably mounting the pole-pieces of the ringer. 1 I w As thusillustrated, my invention comprises an upper bracket-plate A upon whichare mounted the gongs B, the said plate being adapted to be secured uponthe box or casing of a telephone, or upon any other support. Posts aaresecured to thesaid bracket-plate, and to the lower ends of theseposts there is secured an armature mounting C which is preferably ofbrass or other diamagnetic material. The said mounting Specificajtion ofLetters .Patent.

PatentedDec. 1 1914.

" Application filed ane-r 0, 190s. Serial No. 465,021.

is provided at front and rear with depending portions 0, and its upperflat portions are secured by screws 0 tothe upper ends of the magnetcores D. Between the said mounting (J and the upper ends ofthe magnetcores there are clamped the polepiece's E, the same being held in placeby "the saidscrews, and also by means of the rotatable cams or eccentricpins 6, as shown more clearly in Fig. 4. WVhen the sorewsc' areloosened, then these cams or eccentrics e, which have their largerdiameters adapted to rotate. in round openings in the mounting C, may berotated to cause the twopolepieces E to move toward or away from eachother, it being observed that this gives I a very delicate and niceadjustment. The

opening in the pole-piece E which is engaged by the smallerdiameter ofthe cam e 1s m the form of a transverse'slot, so as to allow this pintohave a lateral motion with respect to thep'ole-piece. Thepole-piecesE Iarepreventedfrom moving sidewise by the overturned edges ofthe mountingC. The armature Fis provided'with knife edges 7 which rest in V-shapednotches in the portions 0, and the upper end of said armature isprovidedwith a striker f, which latter is disposed between the two 'gongs; The"lower end of said armature is provided with an eye 7 to which isattached the upper end of a coil spring G, as illustrated.

The lower ends of the magnet coils are connected together by a yoke H ofparamagnetic material, and to this yoke is attached the lower end of apermanent magnet I, whereby the upper pole-pieces of the magnet arepolarized in the well-known manner. A screw I J extends upwardly throughthe central portion of the yoke H,

I and has its upper end provided with a hook to which is fastened thelower end of the spring G, as showninore clearly in Fig. l. A thumb-nutj is applied to the said screw and adapted to bear upon the undersurface of the yoke H, whereby the tension of the spring G may beregulated at will, asby rotating the nut 9' one way or the other. Asplit collar y" surrounds the upper cylindric portion of the nut j, andis provided with a screw y' for clamping the same thereon, whereby thecollar and the nut become solid current to cause the e armature dlsposedbetween he fore 'oin construction and arg ment 1!: W111 be eat a 0Illinois, this 25th day'of N0V., JOHN ER Witnesses:

f ALBOT G. MARTIN, nu {Ann D. FALES

